The ultimate goal of this research is to develop models to predict the structure of RNA molecules from their sequence. Many diseases are mediated through RNA, and the ability to predict their structure will lead to the rational design of drugs. The specific aim of this proposal is to characterize the thermodynamic stability of RNA motifs. The specific motifs to be investigated are: 1. Bulge loops 2. Hairpin loops 3. Dangling end and terminal mismatches. These studies will combine both thermodynamic and structural characterization of RNAs to achieve a better understanding of the nature of RNA stability.